int double char sum 都什么时候用

c\u8bed\u8a00 \u4ec0\u4e48\u65f6\u5019\u7528int float double char\u2026\u2026\u4e4b\u7c7b\u7684\u554a

\u7b2c2\u7ae0 \u6570\u636e\u7c7b\u578b\u3001\u8fd0\u7b97\u7b26\u4e0e\u8868\u8fbe\u5f0f
\u672c\u7ae0\u4e3b\u8981\u4ecb\u7ecdC\u8bed\u8a00\u7684\u5404\u79cd\u6570\u636e\u7c7b\u578b\u3001\u8fd0\u7b97\u7b26\u548c\u8868\u8fbe\u5f0f\u3002
2.1 C\u8bed\u8a00\u7684\u6570\u636e\u7c7b\u578b
C\u8bed\u8a00\u7684\u6570\u636e\u7c7b\u578b\u5177\u4f53\u5206\u7c7b\u5982\u4e0b\uff1a
 \u57fa\u672c\u7c7b\u578b\uff1a\u5206\u4e3a\u6574\u578b\u3001\u5b9e\u578b\uff08\u53c8\u79f0\u6d6e\u70b9\u578b\uff09\u3001\u5b57\u7b26\u578b\u548c\u679a\u4e3e\u578b\u56db\u79cd\u3002
 \u6784\u9020\u7c7b\u578b\uff1a\u5206\u4e3a\u6570\u7ec4\u7c7b\u578b\u3001\u7ed3\u6784\u7c7b\u578b\u548c\u5171\u7528\u7c7b\u578b\u4e09\u79cd\u3002
 \u6307\u9488\u7c7b\u578b
 \u7a7a\u7c7b\u578b
2.2 \u5e38\u91cf\u548c\u53d8\u91cf
2.2.1 \u5e38\u91cf
1\u3001\u5e38\u91cf\u7684\u6982\u5ff5\uff1a\u5728\u7a0b\u5e8f\u8fd0\u884c\u8fc7\u7a0b\u4e2d\uff0c\u5176\u503c\u4e0d\u80fd\u88ab\u6539\u53d8\u7684\u91cf\u79f0\u4e3a\u5e38\u91cf
2\u3001 \u5e38\u91cf\u7684\u5206\u7c7b\uff1a
 \u6574\u578b\u5e38\u91cf
 \u5b9e\u578b\u5e38\u91cf
 \u5b57\u7b26\u5e38\u91cf
 \u7b26\u53f7\u5e38\u91cf
3\u3001\u5e38\u91cf\u7684\u7c7b\u578b\uff0c\u53ef\u901a\u8fc7\u4e66\u5199\u5f62\u5f0f\u6765\u5224\u522b\u3002
2.2.2 \u53d8\u91cf
1\u3001\u53d8\u91cf\u7684\u6982\u5ff5\uff1a\u5728\u7a0b\u5e8f\u8fd0\u884c\u8fc7\u7a0b\u4e2d\uff0c\u5176\u503c\u53ef\u4ee5\u88ab\u6539\u53d8\u7684\u91cf\u79f0\u4e3a\u53d8\u91cf
2\u3001\u53d8\u91cf\u540d\uff1a\u6bcf\u4e2a\u53d8\u91cf\u90fd\u5fc5\u987b\u6709\u4e00\u4e2a\u540d\u5b57\u2014\u2014\u53d8\u91cf\u540d\uff0c\u53d8\u91cf\u547d\u540d\u9075\u5faa\u6807\u8bc6\u7b26\u547d\u540d\u89c4\u5219
3\u3001\u53d8\u91cf\u503c\uff1a\u5728\u7a0b\u5e8f\u8fd0\u884c\u8fc7\u7a0b\u4e2d\uff0c\u53d8\u91cf\u503c\u5b58\u50a8\u5728\u5185\u5b58\u4e2d\u3002\u5728\u7a0b\u5e8f\u4e2d\uff0c\u901a\u8fc7\u53d8\u91cf\u540d\u6765\u5f15\u7528\u53d8\u91cf\u7684\u503c
4\u3001\u6807\u8bc6\u7b26\u547d\u540d\u89c4\u5219\uff1a
 \u53ea\u80fd\u7531\u5b57\u6bcd\u3001\u6570\u5b57\u548c\u4e0b\u5212\u7ebf\u7ec4\u6210\uff0c\u4e14\u4ee5\u5b57\u6bcd\u6216\u4e0b\u5212\u7ebf\u5f00\u5934
 \u6709\u6548\u957f\u5ea6\uff1a\u968f\u7cfb\u7edf\u800c\u5f02\uff0c\u4f46\u81f3\u5c11\u524d8\u4e2a\u5b57\u7b26\u6709\u6548\u3002\u5982\u679c\u8d85\u957f\uff0c\u5219\u8d85\u957f\u90e8\u5206\u88ab\u820d\u5f03
 C\u8bed\u8a00\u7684\u5173\u952e\u5b57\u4e0d\u80fd\u7528\u4f5c\u53d8\u91cf\u540d
 \u6ce8\u610f\uff1aC\u8bed\u8a00\u5bf9\u82f1\u6587\u5b57\u6bcd\u7684\u5927\u5c0f\u654f\u611f\uff0c\u5373\u540c\u4e00\u5b57\u6bcd\u7684\u5927\u5c0f\u5199\uff0c\u88ab\u8ba4\u4e3a\u662f\u4e24\u4e2a\u4e0d\u540c\u7684\u5b57\u7b26\u3002
\u4e60\u60ef\u4e0a\uff0c\u53d8\u91cf\u540d\u548c\u51fd\u6570\u540d\u4e2d\u7684\u82f1\u6587\u5b57\u6bcd\u7528\u5c0f\u5199\uff0c\u4ee5\u589e\u52a0\u53ef\u8bfb\u6027\u3002
5\u3001\u53d8\u91cf\u7684\u5b9a\u4e49\u4e0e\u521d\u59cb\u5316
\u5728C\u8bed\u8a00\u4e2d\uff0c\u8981\u6c42\u5bf9\u6240\u6709\u7528\u5230\u7684\u53d8\u91cf\uff0c\u5fc5\u987b\u5148\u5b9a\u4e49\u3001\u540e\u4f7f\u7528\uff1b\u4e14\u79f0\u5728\u5b9a\u4e49\u53d8\u91cf\u7684\u540c\u65f6\u8fdb\u884c\u8d4b\u521d\u503c\u7684\u64cd\u4f5c\u4e3a\u53d8\u91cf\u521d\u59cb\u5316\u3002
\uff081\uff09\u53d8\u91cf\u5b9a\u4e49\u7684\u4e00\u822c\u683c\u5f0f
\u6570\u636e\u7c7b\u578b \u53d8\u91cf\u540d[, \u53d8\u91cf\u540d2\u2026\u2026];

\u4f8b\u5982\uff0cfloat radius, length, area;
\uff082\uff09\u53d8\u91cf\u521d\u59cb\u5316\u7684\u4e00\u822c\u683c\u5f0f
\u6570\u636e\u7c7b\u578b \u53d8\u91cf\u540d[=\u521d\u503c][, \u53d8\u91cf\u540d2[=\u521d\u503c2]\u2026\u2026];
\u4f8b\u5982\uff0cfloat radius=2.5, length, area;
2.3 \u6574\u578b\u6570\u636e
2.3.1 \u6574\u578b\u53d8\u91cf
1\u3001\u5206\u7c7b
\u6839\u636e\u5360\u7528\u5185\u5b58\u5b57\u8282\u6570\u7684\u4e0d\u540c\uff0c\u6574\u578b\u53d8\u91cf\u53c8\u5206\u4e3a4\u7c7b\uff1a
\uff081\uff09\u57fa\u672c\u6574\u578b\uff08\u7c7b\u578b\u5173\u952e\u5b57\u4e3aint\uff09\u3002
\uff082\uff09\u77ed\u6574\u578b\uff08\u7c7b\u578b\u5173\u952e\u5b57\u4e3ashort [int]\uff09\u3002
\uff083\uff09\u957f\u6574\u578b\uff08\u7c7b\u578b\u5173\u952e\u5b57\u4e3along [int]\uff09\u3002
\uff084\uff09\u65e0\u7b26\u53f7\u6574\u578b\u3002\u65e0\u7b26\u53f7\u578b\u53c8\u5206\u4e3a\u65e0\u7b26\u53f7\u57fa\u672c\u6574\u578b\uff08unsigned [int]\uff09\u3001\u65e0\u7b26\u53f7\u77ed\u6574\u578b\uff08unsigned short\uff09\u548c\u65e0\u7b26\u53f7\u957f\u6574\u578b\uff08unsigned long\uff09\u4e09\u79cd\uff0c\u53ea\u80fd\u7528\u6765\u5b58\u50a8\u65e0\u7b26\u53f7\u6574\u6570\u3002
2\u3001\u5360\u7528\u5185\u5b58\u5b57\u8282\u6570\u4e0e\u503c\u57df
\u4e0a\u8ff0\u5404\u7c7b\u578b\u6574\u578b\u53d8\u91cf\u5360\u7528\u7684\u5185\u5b58\u5b57\u8282\u6570\uff0c\u968f\u7cfb\u7edf\u800c\u5f02\u3002\u572816\u4f4d\u64cd\u4f5c\u7cfb\u7edf\u4e2d\uff0c\u4e00\u822c\u75282\u5b57\u8282\u8868\u793a\u4e00\u4e2aint\u578b\u53d8\u91cf\uff0c\u4e14long\u578b\uff084\u5b57\u8282\uff09\u2265int\u578b\uff082\u5b57\u8282\uff09\u2265short\u578b\uff082\u5b57\u8282\uff09\u3002
\u663e\u7136\uff0c\u4e0d\u540c\u7c7b\u578b\u7684\u6574\u578b\u53d8\u91cf\uff0c\u5176\u503c\u57df\u4e0d\u540c\u3002\u5360\u7528\u5185\u5b58\u5b57\u8282\u6570\u4e3an\u7684\uff08\u6709\u7b26\u53f7\uff09\u6574\u578b\u53d8\u91cf\uff0c\u5176\u503c\u57df\u4e3a\uff1a-2n*8-1~\uff082n*8-1-1\uff09\uff1b\u65e0\u7b26\u53f7\u6574\u578b\u53d8\u91cf\u7684\u503c\u57df\u4e3a\uff1a0~\uff082n*8-1\uff09\u3002
\u4f8b\u5982\uff0cPC\u673a\u4e2d\u7684\u4e00\u4e2aint\u578b\u53d8\u91cf\uff0c\u5176\u503c\u57df\u4e3a-22*8-1~\uff0822*8-1-1\uff09\uff0c\u5373-32768~32767\uff1b\u4e00\u4e2aunsigned\u578b\u53d8\u91cf\u7684\u503c\u57df\u4e3a\uff1a0~\uff0822*8-1\uff09\uff0c\u53730~65535\u3002
\u7b2c2\u7ae0 \u6570\u636e\u7c7b\u578b\u3001\u8fd0\u7b97\u7b26\u4e0e\u8868\u8fbe\u5f0f
\u672c\u7ae0\u4e3b\u8981\u4ecb\u7ecdC\u8bed\u8a00\u7684\u5404\u79cd\u6570\u636e\u7c7b\u578b\u3001\u8fd0\u7b97\u7b26\u548c\u8868\u8fbe\u5f0f\u3002
2.1 C\u8bed\u8a00\u7684\u6570\u636e\u7c7b\u578b
C\u8bed\u8a00\u7684\u6570\u636e\u7c7b\u578b\u5177\u4f53\u5206\u7c7b\u5982\u4e0b\uff1a
 \u57fa\u672c\u7c7b\u578b\uff1a\u5206\u4e3a\u6574\u578b\u3001\u5b9e\u578b\uff08\u53c8\u79f0\u6d6e\u70b9\u578b\uff09\u3001\u5b57\u7b26\u578b\u548c\u679a\u4e3e\u578b\u56db\u79cd\u3002
 \u6784\u9020\u7c7b\u578b\uff1a\u5206\u4e3a\u6570\u7ec4\u7c7b\u578b\u3001\u7ed3\u6784\u7c7b\u578b\u548c\u5171\u7528\u7c7b\u578b\u4e09\u79cd\u3002
 \u6307\u9488\u7c7b\u578b
 \u7a7a\u7c7b\u578b
2.2 \u5e38\u91cf\u548c\u53d8\u91cf
2.2.1 \u5e38\u91cf
1\u3001\u5e38\u91cf\u7684\u6982\u5ff5\uff1a\u5728\u7a0b\u5e8f\u8fd0\u884c\u8fc7\u7a0b\u4e2d\uff0c\u5176\u503c\u4e0d\u80fd\u88ab\u6539\u53d8\u7684\u91cf\u79f0\u4e3a\u5e38\u91cf
2\u3001 \u5e38\u91cf\u7684\u5206\u7c7b\uff1a
 \u6574\u578b\u5e38\u91cf
 \u5b9e\u578b\u5e38\u91cf
 \u5b57\u7b26\u5e38\u91cf
 \u7b26\u53f7\u5e38\u91cf
3\u3001\u5e38\u91cf\u7684\u7c7b\u578b\uff0c\u53ef\u901a\u8fc7\u4e66\u5199\u5f62\u5f0f\u6765\u5224\u522b\u3002
2.2.2 \u53d8\u91cf
1\u3001\u53d8\u91cf\u7684\u6982\u5ff5\uff1a\u5728\u7a0b\u5e8f\u8fd0\u884c\u8fc7\u7a0b\u4e2d\uff0c\u5176\u503c\u53ef\u4ee5\u88ab\u6539\u53d8\u7684\u91cf\u79f0\u4e3a\u53d8\u91cf
2\u3001\u53d8\u91cf\u540d\uff1a\u6bcf\u4e2a\u53d8\u91cf\u90fd\u5fc5\u987b\u6709\u4e00\u4e2a\u540d\u5b57\u2014\u2014\u53d8\u91cf\u540d\uff0c\u53d8\u91cf\u547d\u540d\u9075\u5faa\u6807\u8bc6\u7b26\u547d\u540d\u89c4\u5219
3\u3001\u53d8\u91cf\u503c\uff1a\u5728\u7a0b\u5e8f\u8fd0\u884c\u8fc7\u7a0b\u4e2d\uff0c\u53d8\u91cf\u503c\u5b58\u50a8\u5728\u5185\u5b58\u4e2d\u3002\u5728\u7a0b\u5e8f\u4e2d\uff0c\u901a\u8fc7\u53d8\u91cf\u540d\u6765\u5f15\u7528\u53d8\u91cf\u7684\u503c
4\u3001\u6807\u8bc6\u7b26\u547d\u540d\u89c4\u5219\uff1a
 \u53ea\u80fd\u7531\u5b57\u6bcd\u3001\u6570\u5b57\u548c\u4e0b\u5212\u7ebf\u7ec4\u6210\uff0c\u4e14\u4ee5\u5b57\u6bcd\u6216\u4e0b\u5212\u7ebf\u5f00\u5934
 \u6709\u6548\u957f\u5ea6\uff1a\u968f\u7cfb\u7edf\u800c\u5f02\uff0c\u4f46\u81f3\u5c11\u524d8\u4e2a\u5b57\u7b26\u6709\u6548\u3002\u5982\u679c\u8d85\u957f\uff0c\u5219\u8d85\u957f\u90e8\u5206\u88ab\u820d\u5f03
 C\u8bed\u8a00\u7684\u5173\u952e\u5b57\u4e0d\u80fd\u7528\u4f5c\u53d8\u91cf\u540d
 \u6ce8\u610f\uff1aC\u8bed\u8a00\u5bf9\u82f1\u6587\u5b57\u6bcd\u7684\u5927\u5c0f\u654f\u611f\uff0c\u5373\u540c\u4e00\u5b57\u6bcd\u7684\u5927\u5c0f\u5199\uff0c\u88ab\u8ba4\u4e3a\u662f\u4e24\u4e2a\u4e0d\u540c\u7684\u5b57\u7b26\u3002
\u4e60\u60ef\u4e0a\uff0c\u53d8\u91cf\u540d\u548c\u51fd\u6570\u540d\u4e2d\u7684\u82f1\u6587\u5b57\u6bcd\u7528\u5c0f\u5199\uff0c\u4ee5\u589e\u52a0\u53ef\u8bfb\u6027\u3002
5\u3001\u53d8\u91cf\u7684\u5b9a\u4e49\u4e0e\u521d\u59cb\u5316
\u5728C\u8bed\u8a00\u4e2d\uff0c\u8981\u6c42\u5bf9\u6240\u6709\u7528\u5230\u7684\u53d8\u91cf\uff0c\u5fc5\u987b\u5148\u5b9a\u4e49\u3001\u540e\u4f7f\u7528\uff1b\u4e14\u79f0\u5728\u5b9a\u4e49\u53d8\u91cf\u7684\u540c\u65f6\u8fdb\u884c\u8d4b\u521d\u503c\u7684\u64cd\u4f5c\u4e3a\u53d8\u91cf\u521d\u59cb\u5316\u3002
\uff081\uff09\u53d8\u91cf\u5b9a\u4e49\u7684\u4e00\u822c\u683c\u5f0f
\u6570\u636e\u7c7b\u578b \u53d8\u91cf\u540d[, \u53d8\u91cf\u540d2\u2026\u2026];

\u4f8b\u5982\uff0cfloat radius, length, area;
\uff082\uff09\u53d8\u91cf\u521d\u59cb\u5316\u7684\u4e00\u822c\u683c\u5f0f
\u6570\u636e\u7c7b\u578b \u53d8\u91cf\u540d[=\u521d\u503c][, \u53d8\u91cf\u540d2[=\u521d\u503c2]\u2026\u2026];
\u4f8b\u5982\uff0cfloat radius=2.5, length, area;
2.3 \u6574\u578b\u6570\u636e
2.3.1 \u6574\u578b\u53d8\u91cf
1\u3001\u5206\u7c7b
\u6839\u636e\u5360\u7528\u5185\u5b58\u5b57\u8282\u6570\u7684\u4e0d\u540c\uff0c\u6574\u578b\u53d8\u91cf\u53c8\u5206\u4e3a4\u7c7b\uff1a
\uff081\uff09\u57fa\u672c\u6574\u578b\uff08\u7c7b\u578b\u5173\u952e\u5b57\u4e3aint\uff09\u3002
\uff082\uff09\u77ed\u6574\u578b\uff08\u7c7b\u578b\u5173\u952e\u5b57\u4e3ashort [int]\uff09\u3002
\uff083\uff09\u957f\u6574\u578b\uff08\u7c7b\u578b\u5173\u952e\u5b57\u4e3along [int]\uff09\u3002
\uff084\uff09\u65e0\u7b26\u53f7\u6574\u578b\u3002\u65e0\u7b26\u53f7\u578b\u53c8\u5206\u4e3a\u65e0\u7b26\u53f7\u57fa\u672c\u6574\u578b\uff08unsigned [int]\uff09\u3001\u65e0\u7b26\u53f7\u77ed\u6574\u578b\uff08unsigned short\uff09\u548c\u65e0\u7b26\u53f7\u957f\u6574\u578b\uff08unsigned long\uff09\u4e09\u79cd\uff0c\u53ea\u80fd\u7528\u6765\u5b58\u50a8\u65e0\u7b26\u53f7\u6574\u6570\u3002
2\u3001\u5360\u7528\u5185\u5b58\u5b57\u8282\u6570\u4e0e\u503c\u57df
\u4e0a\u8ff0\u5404\u7c7b\u578b\u6574\u578b\u53d8\u91cf\u5360\u7528\u7684\u5185\u5b58\u5b57\u8282\u6570\uff0c\u968f\u7cfb\u7edf\u800c\u5f02\u3002\u572816\u4f4d\u64cd\u4f5c\u7cfb\u7edf\u4e2d\uff0c\u4e00\u822c\u75282\u5b57\u8282\u8868\u793a\u4e00\u4e2aint\u578b\u53d8\u91cf\uff0c\u4e14long\u578b\uff084\u5b57\u8282\uff09\u2265int\u578b\uff082\u5b57\u8282\uff09\u2265short\u578b\uff082\u5b57\u8282\uff09\u3002
\u663e\u7136\uff0c\u4e0d\u540c\u7c7b\u578b\u7684\u6574\u578b\u53d8\u91cf\uff0c\u5176\u503c\u57df\u4e0d\u540c\u3002\u5360\u7528\u5185\u5b58\u5b57\u8282\u6570\u4e3an\u7684\uff08\u6709\u7b26\u53f7\uff09\u6574\u578b\u53d8\u91cf\uff0c\u5176\u503c\u57df\u4e3a\uff1a-2n*8-1~\uff082n*8-1-1\uff09\uff1b\u65e0\u7b26\u53f7\u6574\u578b\u53d8\u91cf\u7684\u503c\u57df\u4e3a\uff1a0~\uff082n*8-1\uff09\u3002
\u4f8b\u5982\uff0cPC\u673a\u4e2d\u7684\u4e00\u4e2aint\u578b\u53d8\u91cf\uff0c\u5176\u503c\u57df\u4e3a-22*8-1~\uff0822*8-1-1\uff09\uff0c\u5373-32768~32767\uff1b\u4e00\u4e2aunsigned\u578b\u53d8\u91cf\u7684\u503c\u57df\u4e3a\uff1a0~\uff0822*8-1\uff09\uff0c\u53730~65535\u3002
\u5b9e\u578b\u6570\u636e
2.4.1 \u5b9e\u578b\u53d8\u91cf
C\u8bed\u8a00\u7684\u5b9e\u578b\u53d8\u91cf\uff0c\u5206\u4e3a\u4e24\u79cd\uff1a
\uff081\uff09\u5355\u7cbe\u5ea6\u578b\uff1a\u7c7b\u578b\u5173\u952e\u5b57\u4e3afloat\uff0c\u4e00\u822c\u53604\u5b57\u8282\uff0832\u4f4d\uff09\u3001\u63d0\u4f9b7\u4f4d\u6709\u6548\u6570\u5b57\u3002
\uff082\uff09\u53cc\u7cbe\u5ea6\u578b\uff1a\u7c7b\u578b\u5173\u952e\u5b57\u4e3adouble\uff0c\u4e00\u822c\u53608\u4e2a\u5b57\u8282\u3001\u63d0\u4f9b15~16\u4f4d\u6709\u6548\u6570\u5b57\u3002
2.4.2 \u5b9e\u578b\u5e38\u91cf
1\u3001\u8868\u793a\u5f62\u5f0f
\u5b9e\u578b\u5e38\u91cf\u5373\u5b9e\u6570\uff0c\u5728C\u8bed\u8a00\u4e2d\u53c8\u79f0\u6d6e\u70b9\u6570\uff0c\u5176\u503c\u6709\u4e24\u79cd\u8868\u8fbe\u5f62\u5f0f\uff1a
\uff081\uff09\u5341\u8fdb\u5236\u5f62\u5f0f\uff1a\u4f8b\u59823.14\u30019.8\u3002
\uff082\uff09\u6307\u6570\u5f62\u5f0f\uff1aE\uff08e\uff09\u3002\u4f8b\u59823.0E+5\u7b49\u3002
2\u3001\u5173\u4e8e\u7c7b\u578b
\u5b9e\u578b\u5e38\u91cf\u4e0d\u5206float\u578b\u548cdouble\u578b\u3002\u4e00\u4e2a\u5b9e\u578b\u5e38\u91cf\uff0c\u53ef\u4ee5\u8d4b\u7ed9\u4e00\u4e2a\u5b9e\u578b\u53d8\u91cf\uff08float\u578b\u6216double\u578b\uff09\u3002
2.5 \u5b57\u7b26\u578b\u6570\u636e
2.5.1 \u5b57\u7b26\u5e38\u91cf
1\u3001\u5b57\u7b26\u5e38\u91cf\u7684\u5b9a\u4e49
\u7528\u4e00\u5bf9\u5355\u5f15\u53f7\u62ec\u8d77\u6765\u7684\u5355\u4e2a\u5b57\u7b26\uff0c\u79f0\u4e3a\u5b57\u7b26\u5e38\u91cf\u3002
\u4f8b\u5982\uff0c\u2018A\u2019\u3001\u20181\u2019\u3001\u2018\uff0b\u2019\u7b49\u3002
2\u3001\u8f6c\u4e49\u5b57\u7b26
C\u8bed\u8a00\u8fd8\u5141\u8bb8\u4f7f\u7528\u4e00\u79cd\u7279\u6b8a\u5f62\u5f0f\u7684\u5b57\u7b26\u5e38\u91cf\uff0c\u5c31\u662f\u4ee5\u53cd\u659c\u6760\u201c\ \u201d\u5f00\u5934\u7684\u8f6c\u4e49\u5b57\u7b26\u3002
\u6ce8\u610f\uff1a\u5982\u679c\u53cd\u659c\u6760\u6216\u5355\u5f15\u53f7\u672c\u8eab\u4f5c\u4e3a\u5b57\u7b26\u5e38\u91cf\uff0c\u5fc5\u987b\u4f7f\u7528\u8f6c\u4e49\u5b57\u7b26\uff1a\u2018\\\u2019\u3001\u2018\\u2019\u2018\u3002
[\u6848\u4f8b2.1] \u7528\u8f6c\u4e49\u5b57\u7b26\u8f93\u51fa\u53ef\u6253\u5370\u5b57\u7b26\u548c\u4e0d\u53ef\u6253\u5370\u5b57\u7b26\u3002
main()
{
printf(\u201c\x4F\x4B\x21\n\u201d); /* \u7b49\u4ef7\u4e8eprintf(\u201cOK!\n\u201d); */
printf(\u201c\x15 \xAB\n\u201d);
}

\u7a0b\u5e8f\u8fd0\u884c\u7ed3\u679c\u5982\u4e0b\uff1a
OK\uff01
2.5.2 \u5b57\u7b26\u53d8\u91cf
\u5b57\u7b26\u53d8\u91cf\u7684\u7c7b\u578b\u5173\u952e\u5b57\u4e3achar\uff0c\u4e00\u822c\u5360\u75281\u5b57\u8282\u5185\u5b58\u5355\u5143\u3002
1.\u53d8\u91cf\u503c\u7684\u5b58\u50a8
\u5b57\u7b26\u53d8\u91cf\u7528\u6765\u5b58\u50a8\u5b57\u7b26\u5e38\u91cf\u3002\u5c06\u4e00\u4e2a\u5b57\u7b26\u5e38\u91cf\u5b58\u50a8\u5230\u4e00\u4e2a\u5b57\u7b26\u53d8\u91cf\u4e2d\uff0c\u5b9e\u9645\u4e0a\u662f\u5c06\u8be5\u5b57\u7b26\u7684ASCII\u7801\u503c\uff08\u65e0\u7b26\u53f7\u6574\u6570\uff09\u5b58\u50a8\u5230\u5185\u5b58\u5355\u5143\u4e2d\u3002

\u4f8b\u5982\uff0c
char ch1, ch2; /*\u5b9a\u4e49\u4e24\u4e2a\u5b57\u7b26\u53d8\u91cf\uff1ach1\uff0cch2*/
ch1=\u2019a\u2019; ch2=\u2019b\u2019; /*\u7ed9\u5b57\u7b26\u53d8\u91cf\u8d4b\u503c*/
2.\u7279\u6027
\u5b57\u7b26\u6570\u636e\u5728\u5185\u5b58\u4e2d\u5b58\u50a8\u7684\u662f\u5b57\u7b26\u7684ASCII\u7801\u2014\u2014 \u4e00\u4e2a\u65e0\u7b26\u53f7\u6574\u6570\uff0c\u5176\u5f62\u5f0f\u4e0e\u6574\u6570\u7684\u5b58\u50a8\u5f62\u5f0f\u4e00\u6837\uff0c\u6240\u4ee5C\u8bed\u8a00\u5141\u8bb8\u5b57\u7b26\u578b\u6570\u636e\u4e0e\u6574\u578b\u6570\u636e\u4e4b\u95f4\u901a\u7528\u3002
\uff081\uff09\u4e00\u4e2a\u5b57\u7b26\u578b\u6570\u636e\uff0c\u65e2\u53ef\u4ee5\u5b57\u7b26\u5f62\u5f0f\u8f93\u51fa\uff0c\u4e5f\u53ef\u4ee5\u6574\u6570\u5f62\u5f0f\u8f93\u51fa\u3002
[\u6848\u4f8b2.2] \u5b57\u7b26\u53d8\u91cf\u7684\u5b57\u7b26\u5f62\u5f0f\u8f93\u51fa\u548c\u6574\u6570\u5f62\u5f0f\u8f93\u51fa\u3002
main()
{
char ch1,ch2;
ch1='a'; ch2='b';
printf(\u201cch1=%c,ch2=%c\n\u201d,ch1,ch2);
printf(\u201cch1=%d,ch2=%d\n\u201d,ch1,ch2);
}
\u7a0b\u5e8f\u8fd0\u884c\u7ed3\u679c\uff1a
ch1=a,ch2=b
ch1=97,ch2=98
\uff082\uff09\u5141\u8bb8\u5bf9\u5b57\u7b26\u6570\u636e\u8fdb\u884c\u7b97\u672f\u8fd0\u7b97\uff0c\u6b64\u65f6\u5c31\u662f\u5bf9\u5b83\u4eec\u7684ASCII\u7801\u503c\u8fdb\u884c\u7b97\u672f\u8fd0\u7b97\u3002
[\u6848\u4f8b2.3] \u5b57\u7b26\u6570\u636e\u7684\u7b97\u672f\u8fd0\u7b97\u3002
main()
{
char ch1,ch2;
ch1=\u2018a\u2019; ch2=\u2018B\u2019;
printf(\u201cch1=%c,ch2=%c\n\u201d,ch1-32,ch2+32); /*\u5b57\u6bcd\u7684\u5927\u5c0f\u5199\u8f6c\u6362*/
/*\u7528\u5b57\u7b26\u5f62\u5f0f\u8f93\u51fa\u4e00\u4e2a\u5927\u4e8e256\u7684\u6570\u503c*/
printf("ch1+200=%d\n", ch1+200);
printf("ch1+200=%c\n", ch1+200);
printf("ch1+256=%d\n", ch1+256);
printf("ch1+256=%c\n", ch1+256);
}

\u7a0b\u5e8f\u8fd0\u884c\u7ed3\u679c\uff1a
ch1=A,ch2=b
ch1+200=297
ch1+200=)
ch1+256=353
ch1+256=a

char \u662f\u5b57\u7b26
int \u6709\u7b26\u53f7\u6574\u6570\uff0c\u6839\u636e\u7cfb\u7edf32bits\uff0c64bits\u4e0d\u540c\uff0c\u6709\u4e0d\u540c\u7684\u8303\u56f4\u3002
float, double\u662f\u6d6e\u70b9\u578b\u548c\u53cc\u7cbe\u5ea6\u578b\uff0c\u8868\u793a\u5c0f\u6570\uff0c\u533a\u522b\u662f\u7cbe\u5ea6\u4e0d\u540c
\u7cbe\u5ea6\u8981\u6c42\u8f83\u9ad8\u65f6\u7528double

int是整型，一般处理的是整数的时候用到；double是双精度浮点型（12位，float是单精度，6位）；char是字符型，一般和字符或字符窜有关；它们都是c语言的数据类型
需要用到的时候用。sum一般在是用来求和的。

int是整型；double是双精度浮点型；char是字符型；它们都是c语言的数据类型
需要用到的时候用。sum一般在程序中是求和的意思，就是定义一个变量sum用来存储求和的结果；需要求和的程序一般都会用到

这得看你的实际情况，int是整型，double是双精度型，char是字符型

扩展阅读：xbox series x ... 16 personality ... int x 12 double y ... texas instruments ... macbook pro 16 ... matebook14 ... hp elitebook 840 ... i人和e人测试 ... apple 15 pro max ...